1. The Department of Physiology, University of New England (J.R.M.), Armidale, New South Wales 2351, Australia
2. Institute of Reproduction and Development (L.M.F., A.E.O.’C., D.J.P., D.M.d.K.), Monash University, Clayton, Victoria 3168
3. The Departments of Physiology (G.J.), Monash University, Clayton, Victoria 3168
4. Biochemistry and Molecular Biology (M.T.W.H.), Monash University, Clayton, Victoria 3168